The prior art shows many devices for photographing images from two positions separated by an interocular distance to form right and left adjacent images onto a frame of a film strip, one above the other or side by side; or two cameras for photographing right and left images from two positions separated by an interocular distance onto two film strips; subsequently the corresponding right and left images on frames from these two film strips were combined by uniform or anamorphic reduction to form right and left adjacent images side by side or one over the other on a single frame of a single film strip. In the former, mechanical devices such as rotating mirrors or shutters with reflecting or prism beam splitters, or a double lens system was used. These former devices were complex, lacked control of essential variables, or were limited in angular aperture. In the latter, the process of of combining two film strips onto a single film strip was costly because of the use of two film strips, and the precision registration and reduction techniques required. These difficulties inhibited the production of 3-dimensional motion pictures.
The present invention overcomes the difficulties of the prior art by a device which uses a conventional single strip motion picture camera with a single lens, and which provides a wide angle aperture, adjustable convergence and focal length. The device of the present invention contains no mechanical moving parts such as shutter mechanisms or revolving mirrors. The device comprises relatively simple and inexpensive optical elements in a compact unit attached to a standard monocular camera, preferably of the reflex type, to enable the scene to be photographed while simultaneously presenting the right and left adjacent images to the cameraman, so that the convergence and focal length may be adjusted as required.
It is an object of this invention to provide a simple inexpensive optical device to adapt a monocular motion picture camera for the photography of 3-dimensional motion pictures.
It is an object of this invention to employ a single lens with mutually extinguishing pairs of filters before and after the lens to image right and left adjacent images on a single frame of the film at the gate, and at a reflex viewfinder.
It is an object of this invention to provide an optical device for adapting a monocular motion picture camera for the photography of 3-dimensional motion pictures in which the convergence, focus, and interocular distance is controlled simultaneously or independently while the scene being photographed is viewed by the cameraman through a reflex viewfinder.
It is an object of this invention to provide a compact optical device which has no moving mechanical parts other than the angular or distance adjustments of its optical elements for photographing right and left adjacent images onto a single frame of a single strip film.
It is also an object of this invention to provide a binocular viewer or viewfinder to fuse adjacent stereo image pairs into a 3-D image in a viewing device.